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A214777
McNugget numbers: numbers of the form 6*x + 9*y + 20*z for nonnegative integers x, y, z.
3
0, 6, 9, 12, 15, 18, 20, 21, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86
OFFSET
1,2
COMMENTS
A214772(a(n)) > 0;
complement of A065003; all numbers greater than 43 are McNugget numbers: Frobenius(6,9,20) = 43.
LINKS
Scott Chapman, Christopher O'Neill, Factoring in the Chicken McNugget monoid, arXiv:1709.01606 [math.AC], 2017.
Anita Wah and Henri Picciotto, Lesson in Algebra: Themes, Tools, Concepts
Eric Weisstein's World of Mathematics, Frobenius Number.
Eric Weisstein's World of Mathematics, McNugget Numbers.
Wikipedia, Coin problem
FORMULA
G.f.: -x^2*(x^22-x^21+x^17-x^16+x^15-x^14+x^13-x^12+x^11-x^10+x^9+x^8-2*x^7+x^6+x^5+3*x-6) / (x-1)^2. [Colin Barker, Dec 13 2012]
a(n) = n + 21 for n >= 23. - Robert Israel, May 01 2015
MATHEMATICA
CoefficientList[Series[- x (x^22 - x^21 + x^17 - x^16 + x^15 - x^14 + x^13 - x^12 + x^11 - x^10 + x^9 + x^8 - 2 x^7 + x^6 + x^5 + 3 x - 6)/(1 - x)^2, {x, 0, 70}], x] (* Vincenzo Librandi, Apr 27 2015 *)
PROG
(Haskell)
import Data.List (findIndices)
a214777 n = a214777_list !! (n-1)
a214777_list = findIndices (> 0) a214772_list
CROSSREFS
Sequence in context: A262828 A306647 A189728 * A239310 A130699 A099862
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, Jul 28 2012
STATUS
approved